Service call device



July 29, 1941.L w. F. WESLEY ETAL 2,251,180

SERVICE CALL DEVICE Filed July 24, 1959 2 Sheets-Sheet l July 29, 1941.W F WESLEY ETAL 2,251,180

SERVI CE CALL DEVICE .Filed July 24, `1939 2 sheets-sheet 2 I PatentedJuly 29, 1941 SERVICE CALL DEVICE Walter F. Wesley and Ma neapolis,Minn.; said L. Lindsten, Minneap ynard H. Lofback, Min- Wesley assignerto Wilbur ols, Minn.

Application July 24, 1939, Serial No. 286,070

(Cl. .2M-86) 4 Claims.

Our present invention relates to a service call device which may beeither visual or audible, and of a type actuated either directly orindirectly by an impulse produced by the impact of a moving object, suchfor in-stance, as a person stepping on a bag-like mat or the movement ofone or more of the wheels of a vehicle, over an air hose or otheractuator laid across a driveway.

The invention, while intended for general use, is especially welladapted for use in connection with gasoline or other service stationswhere the attendant is often occupied with work where he cannot see avehicle driven up to the dispensing device.

The objects of this invention are to provide a service call devicewhich, when once set into action, by an impulse produced by an impact ofshort duration on an actuator, will continue to operate for a givenperiod of time after the force imparting the impact is no longereective.

Said invention further provides automatic means for controlling theforce of an impulse, irrespective of the weight of the load impartingthe same, or the area on the actuator covered thereby.

The invention still further provides manually operated means for varyingat will, the duration of the signal. A further object of the inventionis to provide means for interrupting the signal so that there are tworelatively short signals instead of one long one. Another object of theinvention is to provide a service call device that will not be affectedby climatic conditions. Other objects of the inventionwill hereinafterappear.

To the above end generally stated, the inven tion consists of the noveldevices and combinations of devices hereinafter described and defined inthe claims.

In the accompanying drawings, which illustrate the invention, likecharacters indicate like parts throughout the several views.

Referring to the drawings- Fig. l is a View partly in elevation andpartly in section showing an installation of the improved device, andalso showing the wiring diagram therefor;

Fig. 2 is a face view of the control unit;

Fig. 3 is a View principally in section taken on the line 3-3 of Fig. 2;

Figs. 4 and 5 are views principally in section taken on the lines 4-4and 5 5 of Fig. 3 respectively;

Fig. 6v is a fragmentary view principally in section taken on the line 66 of Fig. 4, and;

Fig. 7 is a fragmentary view corresponding to Fig. 3 but showing thecontacts separated to interrupt the call or signal during the operationthereof.

For the purpose of showing the invention applied in working position,there is illustrated in the drawings, one of the walls of a building,hereinafter referred to as the service station 8. There is also shown anisland 9 on which is mounted a gasoline dispensing pump IU, some partsbeing broken away. Between the station 8 and the island 9 is an innerdriveway II and outward of said island is an outer driveway I2.

The improved service call device as shown, is an electric bell I3 butmay be a chime or any other suitable signal either audible or visual.This bell I3 may be located anywhere in the station 8 or wherever thesignal will be most eifective. If necessary or desirable, two or more ofthe bells I3 may be interposed in the bell circuit and located atdiierent points, for instance; at a grease pit, shop, or the like.

The electric circuit for the bell I3 includes a normally open switch I4which forms a part of the control unit and is mounted in a roundmetallic box or casing I5 having a removable metallic cover I6,detachably secured thereto by a plurality of screws I1. These screws I1loosely extend through bores in the side wall of the box I5, have screwthreaded engagement with the cover I6 and their heads are countersunk inthe bottom or back of said box. The cover I6 has a capping flange I8which covers the joint between the box I5 and its cover I6. Integralwith the side of the ,box I5 is a pair of diametrically opposite,apertured ears I9 through which screws 20 loosely extend and secure thebox I5 to the inside wall of the station 8. Also integral with the boxI5, at the bottom thereof, is a depending housing 2| for triple valves.

The switch I4 includes cooperating fixed and movable contacts 22 and 23,respectively. Said movable contact 23 is operated to close the switch I4by a diaphragm 24 clamped, at its marginal edge portion, between theopposing rims of the box I5 and its cover I6. This diaphragm 24 affordsan air tight partition between the box I5 and its cover I 6 and forms onone side thereof, within the box I 5, an air compartment 25, and on theother side thereof, within the cover I6, a switch compartment 2S, inwhich the switch I4 is mounted.

Air is forced into the air compartment 25 by one or more impulsesproduced in either one of two hose sections 21 and 28 by the passing ofone or more of the wheels of a vehicle thereover.

These hose sections 21 and 28 are laid transversely across the drivewaysII and I2, respectively, and their adjacent ends are connected acrossthe island 9 by a pipe 29. The other end of the hose section 21 isconnected by a pipe 39 to a coupling 3l in the outer end of a centralbore 32 in the valve housing 2I. A plug 33 closes the outer end of thehose section 28.

Forming a continuation of the bore 32, but of a reduced diameter, is abore-like air chamber 34 into the lower end of which is pressed a sleeve35. Within the air chamber 34 is a ball valve 36 which is gravity seatedon the inner end of the sleeve 35. A port 31, of a lesser diameter thanthe air chamber 34, connects said chamber to the air compartment 25.Obviously, the valve 35 is free to operate between the sleeve 35 and theport S1 but cannot enter the air compartment 25 through the port 31 dueto the reduced diameter of said port. Air forced into the passageway 32from either hose section 21 or 28 will lift the valve 35 from its seatand allow air to enter the air compartment 25 through the port 31 andthen said valve will close to prevent the escape of air from thecompartment 25. In case the valve 35 when open, should accidentally seatin the upper end of the air chamber 34 and thereby close the port 31during the intake of air into the air compartment 25, a by-pass 31connects said chamber to the air compartment for the air.

After air has been expelled from the hose sections 21 and 2S by animpact on one thereof, said sections are again refilled to atmosphericpresstue through an air chamber 3B in the housing 2| at one side of theair chamber 34, and which chamber is connected by a port 39 to the airpassageway 32. A sleeve 49 is pressed into the outer end of the airchamber 38, connects said chamber to atmospheric pressure and a ballvalve 4I in the air chamber 38 is normally gravity seated on the innerend of said sleeve. This valve 4I is free to operate between the sleeve4U and the upper end of the air chamber 38 and cannot enter the port 39due to the reduced diameter thereof. Obviously, partial vacuum producedin one of the hose sections 21 and 28, by air forced therefrom into theair compartment 25 by an impact on one of said sections will lift thevalve 4I from its seat and allow air to flow into the air chamber 38until the hose sections 21 and 29 are again refilled to atmosphericpressure.

To prevent the air compartment 25 from being lled with air beyond apredetermined pressure, we provide a relief ball-valve 42 in an airchamber 43 formed in the housing 2l on the opposite side of thepassageway 32 from the air chamber 39. A sleeve 44 pressed into thelower end of the air chamber 43 connects said chamber to the atmosphereand a port 45 connects the air compartment 25 to the air chamber 43. Thevalve 42 is yieldingly held seated on the inner end of the air chamber43 by a coiled spring 45, compressed between the valve 42 and the sleeve44, and normally closes the port 45.

Air forced into the air compartment 25 as heretofore described, willpress the diaphragm 24 into the switch compartment 25 to close theswitch I4, as will be presently described, and to reduce air pressure insaid compartment and allow the switch to open, there is formed in theside wall of the box I5, a small air vent 41, having a much smaller airconducting capacity than the port 31 and through which vent 41 air inthe compartment 25 gradually escapes until air remaining in saidcompartment is reduced to atmospheric pressure. This air escape vent 41also performs another important function to wit: it permits air toescape from the compartment 25 in hot weather when the same starts toeX- pand and thus prevents sufficient air pressure from being built upin the compartment 25 to operate the diaphragm and thereby close theswitch I4. A breather port 26 in the wall of the cover I5 permits freemovement of air under atmospheric pressure therethrough, during theoperation of the diaphragm 24.

Referring again to the switch I4, its contacts 22 and 23 are each in theform of a leaf spring and which contacts project upright in thecompartment 25 and are anchored at their lower ends to the cover I5 by apost 48 in the form of a headed and nut equipped bolt. The fixed contact22 at the post 48 bears ilatwise and directly against the inner face ofthe cover I6.

A leaf tension spring 49 is interposed between the contacts 22 and 23and is also anchored to the cover I6 by the post 48. The contact 2'3 andthe spring 49 bear directly, the one upon the other, directly engage thepost 48, which extends through bores therein and the nut on said postbears directly on the contact 23. A pair of insulating washers 59insulate the spring 49 from the Contact 22 and also insulate the post 48from said contact and the cover I5.

The contact 23 which is next to the diaphragm 24 has an intermediatehump 5I with which said diaphragm, at its central portion engages. Fixedto the free ends of the contacts 22 and 23 on the opposing faces thereofare cooperating tungsten points which are normally separated. To varythe gap between the points 52 and thereby govern the length of time theswitch I4 remains closed, we provide an adjusting stud This stud 53 hasscrew threaded engagement with the cover I6 and its inner end, whichprojects into the switch compartment 26 impinges against the Contact 22substantially at its longitudinal center. In the outer end of the stud53 is a nick for a screw driver by which said stud may be turned. A locknut 54 on the outer end portion of the stud 53 impinges against thecover IB and holds said stud when set.

An abutment 55 of insulating material interposed between the contacts 22and 23 is xed to the contact 22, between its free end and the stud 53,and normally spaced from the contact 23.

The purpose of this abutment 55 will presently be described.

The electric circuit for the bell I3, includes a battery 55, to one sideof which, said bell is connected by a wire 51; and a wire 58 leadingfrom the other side of said battery is attached to the post 48 andthereby connects the movable contact 23 and its spring 49 to the battery56. The bell I3 is indirectly connected to the xed contact 22 by a wire59 which leads from said bell to a binding post 69, in the form of ascrew that has screw threaded engagement with the cover I6 and fromthence, the circuit is through said cover to the fixed contact 22. Aground wire GI is attached to the binding post G9.

Operation The operation of the above described invention may be brieflydescribed as follows; a Vehicle approaching the pump 9, on either one ofthe driveways II or I2, will pass over the respective hose section 21 or28, and the impact of the wheels thereon will produce one or moreimpulses that force air therefrom and cause the same tok open the valve36 and enter the compartment 25 through the port 31. As air pressure inthe compartment 25 is increased the diaphragm 24 will be pressed againstthe hump I on the movable contact 23 and move the same first intoengagement with the spring 49 which automatically increases the tensionof the Contact 23; further closing movement of said contact will bringits point 52 into engagement with the cooperating point 52 on the Xedcontact 22 and thereby close the switch I4 and complete the bell circuitand start the ringing of the bell I3; still further movement of thecontact 23 by the diaphragm 24 will bring the same into engagement withthe abutment 55. Pressure of the movable contact 23 on the abutment 55,under the action of the expanding diaphragm 24, will spring its free endportion away from the contact 22 and thereby separate the points 52, seeFig. 7, and thus interrupt the signal, or in other words, stop theringing of the bell I3.

As air pressure in the compartment is built up, it starts to escape toatmosphere through the Vent 41 but of course at a much slower rate thanthat at which it enters the compartment 25 through the port 31.

As air pressure in the compartment 25 is reduced, by its escape throughthe vent 41, the movable contact 23, which at this time is held underconsiderable tension by the diaphragm 24, will start to overcome airpressure on said diaphragm and return said diaphragm to normal position.During the initial return movement of the contact 23 it moves out ofengagement with the abutment and again brings its` point 52 intore-engagement with the point 52 on the xcd contact 22, this againcompletes the bell circuit, and starts the second half of the signal orthe ring of the bell I3. Continued return movement of the contact 23will finally open the switch I4 by separating the points 52 and therebycomplete the call or signal.

Adjusting the stud 53 to move the fixed contact 22 toward the movableContact 23, will retard the opening of the switch and thereby increasethe length of the call or signal. A reverse movement of the stud 53 willseparate the contacts 22 and 23 thereby decreasing the length of thecall or signal. The release valve 42 will compensate for variable airpressure, produced in the compartment 25 by the different number oftires passing over one of the hose sections 21 and 28, or by tires ofdifferent sizes, or by vehicles having dual tires, or by vehiclescarrying loads of different weights.

The primary object of the spring 49 is to increase the tension of themovable contact 23 as the same is moved toward the contact 22 andthereby prevent the switch I4 from being closed by a person stepping onone of the hose sections 21 and 28 or by a bicycle being riddenthereover.

During the ination of the hose sections 21 and 28 the ball valve 36 issecurely held on its seat by air pressure in the compartment 25 and bysuction produced thereon by air moving downward through the passageway32 from the port 40.

By embodying the entire device, except the bell and actuator, in aself-contained unit, the installation of the call device is a relativelysimple and easy matter.

From the above description, it is evident that by the novel control ofthe air pressure in the compartment 25 and the novel construction oi theswitch I4, air pressure built up in said compartment will hold theswitch closed and thereby cause the bell I3 to ring for a considerabletime after the tire or tires of a vehicle have passed over one of thehose sections 21 and 28.

Without these novel features the bell I3 would give only a short ring orjingle.

If desired the abutment may be dispensed with and instead of the devicegiving two relatively short calls or signal, a long one will be given.

It will be understood that the invention described is capable of variousmodications within the scope of the invention herein disclosed andclaimed.

What we claim is:

1. In a device of the kind described, a casing, a diaphragm dividing thecasing into a switch compartment and an air compartment, an electriccircuit a normally open switch in the switch compartment, said switchcomprising a pair of leaf spring contacts one of which is relativelymovable and arranged to be engaged by the diaphragm, means for adjustingthe other contact relative to the movable contact to vary the normal gapthere-between, means including a conduit for intermittently forcing airinto the air compartment, a check valve in the air conduit arranged tobe opened by air being forced through the conduit to the air compartmentand be closed by air pressure in the air compartment, a second checkvalve in the conduit outward of the first noted check valve and arrangedto be held closed by air pressure in said conduit, and arranged to openwhen air pressure in the air ,conduit is below atmospheric pressure, anair release valve leading from the air compartment and arranged to openwhen air pressure in the air compartment goes above a predeterminedpressure, and an air escape vent leading from the air compartment, andhaving an air conducting capacity that is less than the air intake fromthe conduit.

2. In a device of the class described, a casing, a diaphragm dividingthe casing into a switch compartment and an air compartment, in anelectric circuit a normally open switch constructed and arranged to beclosed by the diaphragm, an air conduit having communication with theair compartment, means for forcing air through said conduit to producean impulse in the air compartment for actuating the diaphragm to closethe switch, a check valve in the conduit arranged to be opened by airpassing through the air conduit to the air compartment, and when closed,preventing the escape of air from the air compartment to the conduit, anopen air escape vent leading from the air compartment to atmosphere, theair-conducting capacity of the Vent being less than the air-conductingcapacity of the air conduit, and an air release valve leading from theair compartment and arranged to open when air pressure in saidcompartment goes above a predetermined pressure.

3. The structure defined in claim 2 which further includes a secondcheck valve outwardly of the rst noted check valve and normally closedby air pressure in the conduit and arranged to open when air pressure inthe conduit drops below atmospheric pressure.

4. In a device of the class described, a diaphragm dividing the casinginto a switch compartment and an air compartment, in an electric circuita normally open switch in the switch compartment, said switch comprisinga relatively iixed contact and a co-operating relatively movablecontact, said movable contact being a leaf spring anchored at one endand with its free end portion arranged to engage the xed Contact byspringing the movable contact toward the fixed contact, an air conduithaving communication with the air compartment, means for forcing airthrough said compartment to produce an impulse in the air compartmentfor actuating the diaphragm, said movable contact being arranged to beengaged by the actuated diaphragm and said movable Contact pressedthereby into engagement with the Xed contact, said switch compartmentbeing open to the atmosphere, an air escape vent leading from the aircompartment to the atmosphere, the air-conducting capacity of the ventbeing less than that of the air intake from the air conduit, and anabutment between the two contacts and arranged to be engaged by themovable contact after said movable contact has been moved intoengagement With the xed contact by the actuated diaphragm during itsinitial movement and spring the movable contact out of engagement withthe fixed contact during nal movement of the movable contact toward theXed contact by the actuated diaphragm, said diaphragm during its initialreceding movement allowing the movable contact to re-engage the xedcontact and during its final receding movement, allowing the movablecontact to again move out of engagement with the xcd Contact.

WALTER F. WESLEY.

MAYNARD H. LOFBACK.

